Method and apparatus for forming curved walls.



B. s. BOWKER. THOD AND APPARATUS FOR FORMING GURVED WALLS.

ME I APPLICATION I'ILED JULY 25, 1912.

Patented July 14, 1914.

Minewast I Til/P71 Z07 g/ /M fly W W ERNEST s. BOWKER, or

CHICAGO, ILLINOIS, ASSIGNOR. OF ONE- s o were 1 EMINGER, or emson our, rots." METHOD AND arraiae'rus iron re ns uneven watts.

mosses.

Specification of ltetters Patent.

Patented, July 14, 1914.

Application filed July 25, 191?. Serial hi0. 711A13.

To all whom it may concern:

Be it known that I, Ennnsr S. Bowman, a citizen of the United States, residing at Chicago, county of Cook, State of Illinois, have invented a certain new and useful Improvement in Methods of and Apparatus for Forming Curved \Valls, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

The ordinary method of making concrete walls is to deposit a mass of comparatively dry concrete into a mold and tamp it; the mold being either large enough to contain the entire wall, or one large enough only to form a section of the wall, the mold being moved after the formation of each section so as to permit an adjacent section to be added.

It is well known that the wetter concrete is the more satisfactory will be the structure made therefrom, but the old methods to which I have referred are not adaptable for extremely wet concrete.

The object of my invention is to produce a simple and reliable process by which a wall of any desired shape may be formed quickly from wet concrete in a liquid or semiliquid state.

A further object of my invention is to produce a simple and novel process of constructing curved or circular concrete walls.

A further object of my invention is to produce a simple and novel process of making a concrete wall and simultaneously reinforcing it.

A further object of my invention is to produce a simple and novel apparatus for carrying out my novel method, viewed in its various aspects.

The various features of novelty whereby my invention is characterized will hereinafter he pointed out with particularity in the claims; but, for a full understanding of my invention and of its various objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein:

Figure l is a side elevation of an apparatus arranged in accordance with my invention for the purpose of producing circular walls in accordance with my improved method, the walls in process of formation being shown in the section; Fig. 2 is a view of the apparatus looking toward the right from the left hand side of Fig. 1, thewalls being omitted.

In carrying out my invention I make use.

of the fact that the wettest concrete may readily be molded or shaped if it is in a layer sufficiently thin. Consequently by applying the wet concrete in thin layers, a layer of any desired length and width can readily be formed and Similar successive layers added on top thereof until. the combined thicknesses of a large number of la are is equal to the height of the wall whic is to be constr cted; the widths of the layers and the le s of the layers determining re.- spective y the thickness and the ion h of the wall. The process may be a su sta l-- tially continuous one, one layer following after another without allowing sufiicient time to elapse to permit any one layer to harden and thus give rise to the danger of a poor oining. For producing a simple circular wall, the entire structure may be built up from a single contin us st ip or rib n arranged like the turns of a helix resti upon one another and permanently unit d to other in the process of formation,

he principle of my invention may be a plied 1n a great many different ways and he embodled 1n machinery or apparatus of a great many different forms. For the sake of brevity, however, have illustrated in the drawmg only a elngle apparatus, namely one for build ng a "plurality of concentric cyllndrical walls which may or may not be reinforced; and fshall confine the detailed descript on to this pqntiw ler of my mventron, as it will of course b und r pcl thatmy .mz e i n, in it broader aspects, 1s not lim ted to any single type of apparatus or to a specific. series of etc, wh ch 1t may be advisable to employ, in carrymg out my invention, in the formation of some specific t e ofwall.

Referring to e drawing, 1 represents a vertical post or stafi on which is revolubly mounted a cross-piece 1 sweep 2. The post 1s set up and rigidly supported at the center of a cylindrical wall or series of concentric cylindrical the sweep is provided at Suitable distances from the axis of rotation with forming and walls to be produced and i shaping devices into which wet concrete may be poured and by which the' concrete may be distributed and shaped into a thin layer or layers as the sweep 1s revolved. By supplying the concrete in sufficient quantities, a

continuous layer will be laid down by each forming and shaping device during a complete revolution of the swee so that whena complete revolution has n made, the sweep "3 must be lifted a height equal to the thickness of the next layer so as to permit a new layer. to be added. This may convenientl'y be accomplished by screw-threading the sweep upon the post so that as the sweep revolves it is slowly lifted and lays down a continuous ribbon or strip of'concrete in the form of a helix having its turns in contact with each other and fastened together. By properly designing the parts, it is only necessary to maintain the supply of wet concrete and to rotate the sweep slowly until it has" automatically risen through a height equal to the height of the wall to be produced, in order to obtain a monolithic wall of uniform texture.

In the particular arrangement illustrated,

the apparatus is designed to make a hollow wall 3 composed of two separated, conce-ntriccylinders and also a smaller cylindrical inner wall 4. The wall 3 isadapted to be built up and shaped by means of devices 5 and 6 in the form of inverted open ended troughs carried on the under side of the sweep and curved on the arc of circles having their centers at the axis of rotation. On the sweep above the members 5 and 6 is a hopper 7 which is adapted to supply the wet concrete to both of these members. On the opposite side of the sweep is' a member 8 corresponding to the members 5 and 6- and adapted to form and shape the wall 4. Above the member 8 is a hopper 9 which supplies the wet concrete thereto. The sides of the members 5, 6 and 8 need not be very deep since I intend to mark each layer only a fraction of an inch in thic ess and therefore the sides of these members need not be over a few inches deep in order to permit them to overlap a finished portion of the wall and to exert a smoothin efi'ect upon the damp portions at the top. n other words, by making the sides of the members 5, 6 and 8 a few inches deep, they will act as smoothing irons which are slid across each piece of the surface of one of the walls a number of times during the process of building the wall and thus a smooth finished surface is obtained. The length of the members 5, 6 and 8 will. of course vary with the character of the work and ma be anything from one foot to three feet; it being only necessary that these members be long enough to confine the liquid or semi-liquid concrete long enough to'permit it to take enough set to remain in place when left alone. Consequently the length of the members 5, 6 and 8 will also depend upon the speed at which wall already formed and level it so that uniformity of thickness will be maintained throughout the length of each layer. I prefer to make the members 10, 11 and 12 in the form of shoes which not only act as leveling devices but work and press down the newly laid concrete so as to insure compactness of the new layer and a perfect union with the wall underneath. I therefore prefer to make the members 10, 11 and 12 extend throu hout the entire lengths of the forming and away only below the discharge opemngsin the hoppers. Furthermore, I prefer so to construct or form the shoes 10, 11 and'12 that they will leave the top surface of each layer comparatively-rough, and thus make it easy to make a perfect union between the top of one layer and the under side of the next succeeding layer. .This may conven-- iently be accomplished" by making the shoes of ordinary rough boards, that is boards having an unplaned under surface.

In some cases it may be well to duplicate the members 5 and 6 on the opposite side of the sweep, as is indicated at 50 and 60, and to duplicate the member 8 on the opposite side of the axis of rotation as indicated at 80. Even though no concrete is supplied to the members 50, 60 and 80, yet these members will serve to counterbalance the apparatus,'will aid in ironing and compacting the freshly laid concrete and will hold the shaping devices, being out apparatus steady so that an uneven effect will not be produced by reason of the risingand falling of the sweep.

For lifting the sweep automatically, I have mounted on the central post a vertically-adjustable sleeve 13 adapted to be held in the desired adjustment by means of a set screw 14, or in any other suitable manner. The exterior of the sleeve is screw threaded as indicated at 15 and the sweep is provided at the center with a hub 16 screw-threaded internally so as to cooperate with the screwthreads on the sleeve.

In starting, the sweep is screwed down to apoint near the lower end of the sleeve, the sleeve is then fastened in place upon the post at the proper elevation to bring the sev eral forming and shaping devices into their working positions. The hoppers are then filled with concrete and the sweep is rotated, laying down wet concrete and shaping it into a thin annular band or ring, the sweep gradually rising so that when the starting point is reached after a complete revolution has been made, a space is left above the newly made layer just high enough to produce a new layer. Thus, as the sweep is slowly rotated, the supp y of wet concrete being maintained, a co tinuous ribbon of concrete is laid down, molded and worked up against and into the underlying material until a wall the desired height is obtained. If the height of the wall is greater than the length of the screw-threaded sleeve, the sleeve is adjusted upwardly from time to time, the sweep being screwed back after each adjustment, so as to bring it to the bottom of the sleeve. Thus we see that each of the forming and shaping devices builds up its own wall, that any one of the walls may be stopped at the desired height and that any desired number of walls may be produced simultaneously.

The arrangement shown is one which can be used to advantage in building circular hollow walls, barns that have silos in the middle, and, by varying the disposition of the forming and shaping devices and the dimensions thereof, any other desired combination of walls may be obtained.

If it is desired to reinforce the concrete this may conveniently be done by mounting on the sweep a reel or reels 17 having their axes at right angles to the axis of rotation at the sweep and adapted to carry wire which may be fed automaticall beneath the sweep on top of one or more 0 the walls as the sweep travels around, thus embedding in one or more of the walls a reinforcing ring. After a complete reinforcing ring has been laid in place, the wire ma be cut and the reels be allowed to stan idle until the height of the wall or walls has been inately after being formed, and then adding,

in the same way, successive layers until a wall of the desired height is reached.

2. The method of forming a concrete wall without the use of a supporting mold which consists in pouring liquid or semi-liquid concrete upon a suitable base so as progressively to form a thin layer or ribbon, confining the concrete as it is poured only momentarily, and then, in the same way, adding successive layers until a wall of the desired height is reached.

3. The method of forming a concrete wall which consists in pouring liquid or semiliquid concrete u on a suitable base so as progressively to orm a uniform layer thin enough to become self-sustaining immediately after being formed, adding, in the same way, successive layers until a wall of the desired height is reached, and smoothing and working the sides of the wall for a considerable distance below the top thereof as each layer is bein formed.

In testimony w ereof, I sign this specification in the presence of two witnesses.

I ERNEST S. BOWKER.

. Witnesses:

WM. F. FREUDENREI H, IIARRY S. GAITHE'R. 

